<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <button id="connect">连接</button>
  <button id="send" disabled="true">发送数据</button> <br>
  从服务端接收的数据如下： <br/>
  <span id="recv"></span>

  <script>
  var connect = document.querySelector('#connect')
  var send = document.querySelector('#send')
  var recv = document.querySelector('#recv')
  let ws = null
  connect.onclick = function () {
    ws = new WebSocket('ws://localhost:9998')
    ws.onopen = () => {
      console.log('连接服务端成功了')
      send.disabled = false
    }
    ws.onclose = () => {
      console.log('连接服务端失败了')
      send.disabled = true
    }
    ws.onmessage = msg => {
      console.log('接收到从服务端发送过来的数据了')
      console.log(msg)
      recv.innerHTML = msg.data
    }
  }
  send.onclick = function () {
    ws.send(JSON.stringify({
      // action: 'getData',
      // socketType: 'trendData',
      // chartName: 'trend',
      // value: ''
      action: 'fullScreen',
      socketType: 'fullScreen',
      chartName: 'trend',
      value: true
    }))
  } 
  </script>
</body>
</html>